Is interstellar travel possible?

[LongTomH]

So many people on this forum believe that the great distance between the stars will always make travel between them impossible; but, a lot of people are disagreeing.

For more ideas, check out Icarus Interstellar.

Edited to add: Here are more cool pics of the IXS Enterprise starship shown in the second video.

[SheilaT]

1. Very, very interesting.

I have a son who has just completed a physics degree and has his applications out for PhD schools in astrophysics. He's coming to visit me for Christmas, and I'm going to have to show these to him.

[Igel]

2. I suspect that most would say it's not impossible.

Just absurdly painful and time-consuming.

Most of the "let's get there fast" methods require a bit of speculation. Things like generational ships are plausible extensions of current tech, but strain credulity as to whether they'd be stable over the time periods necessary to make the trip without having their social structure decay until there'd be no chance of maintaining the infrastructure necessary to guarantee survival.

[SoLeftIAmRight]

14. I really like the generational ship idea

Fun sci fi reads

[MillennialDem]

19. I don't - I think humans will conquer death from aging. Then a slow ship is possible without requiri

ng generations.

Cryonic freezing might also be possible so the ship's occupants don't need to be bored for a 1,000 year trip. (100 ly at 0.1c for example).

[Johonny]

23. Most likely any society that can create a generational ship... won't

because they simple won't need to have anyone living aboard. The machine when it arrives would "make" its crew as needed.

[Half-Century Man]

3. My two cents.

THe first ships should not be named after fictional ships, Presidents, or battles. They should be named for the dreamers who inspired us.
The Roddenberry
The Asimov
The Wells
and for good measure
The Munchhausen

[SCantiGOP]

36. One more name

The Aurthur C Clarke

[Half-Century Man]

37. Most assuredly

It was just a quick and totally lacking list.

[SCantiGOP]

38. I wasn't criticizing your list

Only other name that jumps out at me is the writer who, while pretty simplistic by later standards, introduced me at a young age to science fiction: Jules Verne.

[Half-Century Man]

39. I didn't read your post as a critique.

I was admitting the limits of my post.

By naming our ships in this manner. I just want to set the tone right from the beginning, that we seek our place in our ever expanding universe with open minds; rather than carve out an empire.

[Fluothane]

4. Interstellar travel

Thanks for posting this LongTomH. At some point, if we are to survive as a species, interstellar travel will have to become possible. Even if we survive climate change, the sun will not last forever. Hopefully in the next 5 billion years we will find an alternative to blowing each other up. I think this guy is right though, when humans come together to focus on a task we usually get it done. Hell, we made it to the moon back in 1969. Just think of where we could be now if public interest had not waned from the Apollo program.

[longship]

5. TheSun will wipe out life on Earth in about 1 billion years.

So no. We do not have 5 billion.

The Sun is getting hotter since it started being a star. In about a billion years it will be too hot for life as we know it to live on Earth. That's the physics of the thing.

We'd better hurry with those warp drives. Paging Montgomery Scott!

(No! We will likely never have warp drives. There just isn't any cosmology that makes such a thing possible. Everybody knows that warp drives are only a plot device to get the Enterprise through the next commercial break.)

I highly suspect that the reason why there are no space aliens visiting Earth is that interstellar travel is really, really difficult. So, few, if any, do it. It realistically could be none are doing it because it is that difficult. That is my preferred answer.

[Fumesucker]

8. Plenty of time to move the planet to a more distant orbit

It's not even particularly difficult as such things go. Just fly by a medium sized asteroid every six thousand years or so to add a little kinetic energy to Earth's orbit.

http://abcnews.go.com/Technology/story?id=98500&page=1

[longship]

10. That would work!

Steal some momentum from Jupiter, a little at a time. Add a little to Earth. Over the millions of years the Earth would slowly drift into a larger orbit, and Jupiter would do the opposite but much more slowly because of its huge mass.

And we are really good at kinematics. We can launch a probe towards Saturn with multiple planetary flybys to gain velocity and reduce fuel use. We can put the craft into orbit around Saturn and land a sub probe on one of the moons and keep the main probe orbiting, taking pics and measurements for years, changing its orbit to get close to some of the 60+ bodies orbiting Saturn when we want to.

And that is just the Cassini mission. Don't get me started about what we did in the 70's with the Voyagers, especially Voyager 2 which went by all four gas giants.

Yup! We got this shit down. We could do what you suggest.

We could also change the orbit of an asteroid headed on a collision course with Earth. We'd need some warning time, but we could (as Bill Nye says) get 'er done. That would be the same tech used for your scenerio.

[qazplm]

17. temp fix at best

I think for us, now, interstellar travel is impossible.

I think for us, 100K years from now, assuming even just modest tech advancements along that period of time, it's almost guaranteed.

It may not FTL (although I would not rule that out) but it can certainly be an appreciable fraction of the speed of light...even going at say 40 percent would make it very easy to "hop" from star system to star system...and I find it highly unlikely that we wouldn't be able to solve all the relevant problems in 100K years, again assuming even very modest movement in tech from year to year over that time period.

And we've been anything but modest over the last couple of generations.

[MillennialDem]

22. How would 0.4c make it easy to hop from star system to star system? That's still 10 years to alpha

centauri and the time dilation is negligible (about 9% difference)

Though I think human lifespan will be indefinite relatively soon so long trips may not be a problem. Especially with cryonic sleep / hibernation?

[longship]

6. Yes, but I suspect that few are doing it, if anybody.

And those kooks who talk about warp drives are not doing real science. Everybody knows that the only purpose of a warp drive is to get the Enterprise past the next commercial.

Plus, one cannot ignore the Tsiolkovsky rocket equation, which everybody positing interstellar travel conveniently does ignore. This is basic physics 101, stuff that is not likely to be overturned ever. In Star Trek it was a plot device that everybody basically ignored, just like the transporter ignored the continuity problem -- well, everybody but McCoy.

But as far as anybody who understands basic science, none of this is real, and none of it is likely ever to become real. It is what could be called, a Star Trek wet dream.

However, it does make for a great background for a fictional narrative. That's why Star Trek is so damned compelling and long lived. But it is what it is. Fiction.

I suspect that the reason we have not been visited by space aliens is that interstellar travel is so fucking difficult that virtually nobody is doing it. Also, there's the issue that we live in a really, really huge galaxy and even small interstellar distances are fucking ginormous.

[samson212]

7. Alcubierre drive bypasses classical mechanics concerns...

The whole point of the Alcubierre drive is that there's no thrust involved. Rather than using a conventional engine (with which you're right, it would be impossible to approach relativistic speeds much less accomplish interstellar travel) this kind of engine actually compresses / expands space-time in front of and behind the vehicle. The ship would be in a locally flat region of space-time, i.e. a non-accelerated frame, so the rocket equation is completely irrelevant. You can call them kooks if you want, but it won't stop scientists from investigating the actual science that is involved here.

There are a lot of real issues with the science. An initial problem was that, should the mathematical issues be worked out, the amounts of energy that would theoretically be required to operate such a drive are astronomical. Literally. Like, more than the energy of the entire universe. Recently, theoretical physicists have been able to reduce the requirements to more 'manageable' numbers, to something more like the energy contained in the Voyager 1 probe. Still, you'd have to convert the whole thing to energy, which we don't have a way to do. It's a lot of energy.

Another problem I've heard is that there may not be a way to safely collapse the bubble once you've built it, so you could travel across the universe in the blink of an eye, but you'd just keep right on going out into the void, never being able to return to normal space. I've also heard it said that if you could collapse such a bubble, all of the energy you used to erect it would be catastrophically released, completely annihilating anything nearby...

But this is a real scientific theory. It may be shown to be incorrect when we figure out quantum gravity, but there's definitely real mathematics behind it.

[longship]

9. No thrust means no movement.

And no! There is no warping of space either. That would require massive amounts of energy, as great as the mass of Jupiter some have calculated. (Using E=mc^2)

As I implied, a Star Trek wet dream. And I love Star Trek.

No serious physicist takes the Alcubierre drive seriously. None of them.

I do like the star ship design, though. Cool looking, which like the Enterprise, is scientifically its sole value. Too bad they are fiction.

And no, it is not a real scientific theory as AFAIK it has not been published in any reputable scientific journal. So there's that minor problem. Until it is published, it can be fairly characterized as made up shit. To be blunt about it. Pauli would characterize it more kindly as "not even wrong."

And your post shows why this drive is not being taken seriously.

My best to you.

[qazplm]

18. actually by altering the geometry

they've gotten the amount of energy down well below planet size to a small truck.

I think you are wrong that no "serious physicist" takes it seriously. I think plenty do...now, they may take it serious enough to look at it and say, no can do, but it's not nearly as bat guano crazy as you are trying to make it.

[longship]

12. No thrust == no space travel.

For Christ sakes! Does nobody here understand basic physics?

The rocket equation! (Linked above)

Making up shit just gives one bullshit.

There are no warp drives. Or transporters. They can be fairly characterized as Star Trek wet dreams.

And no. NASA is not funding the Alcubierre drive research. It is true that some NASA dude is promoting it, just not NASA.

Plus, where is the citation to a peer reviewed paper. That's right. It does not exist.

Get your facts right.

[Warpy]

26. I'll wait and see what they figure out is making the em drive work

and whether or not it will work in a vacuum.

[longship]

27. No thrust? No go!

Magic does not work in space any more than on Earth.

EM drive violates Newton's first law.

[Warpy]

29. NASA has determined it does produce thrust

They just have no clue how.

[longship]

31. Well, here's what physicists are saying.

The EMdrive is likely rubbish.

http://www.preposterousuniverse.com/blog/2015/05/26/warp-drives-and-scientific-reasoning/

http://www.popularmechanics.com/science/a15323/temdrive-controversy/

http://www.theskepticsguide.org/4-reasons-why-the-em-drive-is-probably-bullshit

http://rationalwiki.org/wiki/EmDrive



So, yup! Pretty much bullshit.

[LongTomH]

11. A 'Star Trek wet dream'?

NASA funded a study of advanced physics propulsion, including the Alcubierre Warp Drive, under their Breakthrough Propulsion Physics program, from 1996 through 2002. Some of the results of that study were published in Frontiers of Propulsion Science. Marc Millis, who headed up the Breakthrough Propulsion Physics program, went on to found the Tau Zero Foundation, another organization studying interstellar flight.

As for your comment: "It is not a real scientific theory as AFAIK it has not been published in any reputable scientific journal:" Let's take a look at: The quantum inequalities do not forbid spacetime shortcuts in Physical Review, or Alcubierre's paper: The warp drive: hyper-fast travel within general relativity in Classical and Quantum Gravity.

I also recommend you see Dr. Harold White's paper: Warp Field Mechanics 101 published by the Johnson Space Center. Work by Dr. White and others indicates that the energy requirements for a 'warp drive' may be drastically reduced from Dr. Alcubierre's original estimates.

Edited to add: Yes, I am aware of Konstantin_Tsiolkovsky's rocket equation.

[SoLeftIAmRight]

13. How long do you got

I love Lucy has reached many stars

It is my hope that we are able to travel the universe.

[Marrah_G]

15. I believe it is

Once upon a time flying was thought to be fantasy, people thought the world was flat, Wifi, cell phones...all the stuff of science fiction. Within my lifetime I've seen massive leaps forward from fiction to reality, so I do believe. I believe in the human mind, imagination and drive to explore.

[MillennialDem]

20. I believe it is, but I think humans conquering death from aging is a much easier nut to crack than

faster than light travel.

At which point, considerably sub light interstellar travel becomes very possible - and we can already attain 0.1c - 0.25c with nuclear pulse propulsion. Solar sail and fusion drive might also be possible.

[qazplm]

25. while I think FTL travel

is on the border of possible, I agree with you that comparatively, conquering death from aging is much easier, and thus if we can, we might not need FTL travel to colonize the galaxy.

[bvf]

16. Bookmarked. Thanks, LongTomH. n/t

[goldent]

21. Assuming any mission will take multiple generations

it raises all kind of issues, including how to get funding in the present.

[Ichingcarpenter]

24. Yes and its myopic, dogmatic, parochial to say we won't

Hell.......... we don't even know what 95% of our universe is composed of. Dark Energy, Dark Matter, Dark knowledge is more like it.

We don't even know how many dimensions there are and if they might be used for interstellar travel.

[Nailzberg]

28. I hope so. I want off this rock.

[SheilaT]

30. Physicist son says that we are probably

a very long way, as in several hundred years, from any sort of realistic inter-stellar travel. For what his opinion is worth.

A million years from now we probably won't even be around as a species. Maybe our distant descendants will have evolved into something else, maybe we'll have simply died out. Or made our planet uninhabitable long before we can establish self-sustaining colonies anywhere.

I think one of the reasons we have not verifiably been visited by alien civilizations is that either interstellar travel is not possible, or if we have been visited by such it was long, long ago, before we became human, and they didn't bother to colonize this planet.

[ladjf]

32. The human body is mechanically frail.

Interstellar travel requires close to light speed velocities. Assuming that a human could only survive two or three constant G's over a long period of time. The acceleration of the ship would need to be limited to human's abilities to withstand constant G forces greater than 1. I'm not a mathematician so I haven't calculated the actual acceleration times but my intuition is that it would take more than a lifetime to accelerate up to 180,000 miles per second. And then the an equal amount of time to slow to1 G.


I don't believe interstellar travel for humans will ever be possible. But, for robots, most definitely.

[getting old in mke]

33. Doesn't mitigate the other challenges

But 1G acceleration gets close to light speed in about a year.

[ladjf]

34. Thanks for the calculation. I was guessing that it would have taken longer than that. nt

[Octafish]

35. A First Real-World ''Interstellar'' Wormhole?

by DailyGalaxy, Sept. 3, 2015

"Wormholes" are cosmic tunnels that can connect two distant regions of the universe, and have been popularised by the dissemination of theoretical physics and by works of science fiction like Stargate, Star Trek or, more recently, Interstellar. Using present-day technology it would be impossible to create a gravitational wormhole, as the field would have to be manipulated with huge amounts of gravitational energy, which no-one yet knows how to generate. In electromagnetism, however, advances in metamaterials and invisibility have allowed researchers to put forward several designs to achieve this.

Scientists in the Department of Physics at the Universitat Autònoma de Barcelona have designed and created in the laboratory the first experimental wormhole that can connect two regions of space magnetically. This consists of a tunnel that transfers the magnetic field from one point to the other while keeping it undetectable - invisible - all the way.

The magnetic wormhole is an analogy of gravitational ones, as it "changes the topology of space, as if the inner region has been magnetically erased from space", explains Àlvar Sánchez, the lead researcher.

The researchers used metamaterials and metasurfaces to build the tunnel experimentally, so that the magnetic field from a source, such as a magnet or a an electromagnet, appears at the other end of the wormhole as an isolated magnetic monopole. This result is strange enough in itself, as magnetic monopoles - magnets with only one pole, whether north or south - do not exist in nature. The overall effect is that of a magnetic field that appears to travel from one point to another through a dimension that lies outside the conventional three dimensions.

CONTINUED...

http://www.dailygalaxy.com/my_weblog/2015/09/the-first-real-world-interstellar-wormhole.html

PS: Thank you for another great OP and thread, LongTomH. Amazing subject demonstrating the importance of imagination.

[Ichingcarpenter]

40. Greg Meholic Advanced Space Propulsion Concepts for Interstellar Travel

Greg Meholic
Project Engineer at The Aerospace Corporation
Greater Los Angeles AreaDefense & Space

Current
Loyola Marymount University, The Aerospace Corporation

Previous
GE Aviation (Aircraft Engines)

Education
Embry-Riddle Aeronautical University

Projects worked on
Horizon pluto project for NASA

This lecture covers current and future
space travel.... BTW... no woo, no UFOs
just the science, engineering and theories of space and interstellar travel with good diagrams, charts and explanations.... the interstellar part is at the end but
the whole lecture is worth it.